Some of the Zone books do list soy milk and soy imitation products. All you really need to know is that a block of protein = 7 grams and a block of carb = 9 grams.
Vegetarian protein suggestions: tempeh, imitation soy products (Boca burgers, Gimme Lean Sausages, hot dogs), soy crumbles, chesse, soy nuggets that taste like chicken, shimp). Quorn product. Prepared entrées from Cedarlane Natural Foods. Look for Zone Cedarlane frozen foods (do Internet searches). Here’s a start, hope this helps.